Method and apparatus for evaluating retention time of foam of beer

A method for evaluating the period of beer foam stability of sample of equal foam layer thicknesses comprising the steps of obtaining a sample by pouring a fixed amount of prescribed beer into a standard glass from a pouring height calculated to approximate a standard preset thickness, measuring the foam layer thickness and the period of foam stability of the sample, comparing the measured values with the standard foam layer thickness value, adjusting the beer pouring height to approximate the standard foam thickness more closely, pouring the fixed amount of the prescribed beer into a standard glass to obtain another sample, and measuring and storing the foam thickness value and period of foam stability of the sample, and reading the period of foam stability value corresponding to the standard foam layer thickness from a graph obtained by plotting the foam layer thickness data against the period of foam stability data for a plurality of samples obtained by repeating the above steps a number of times.